1. Technical Field
The present disclosure relates to a heat dissipation structure of a projection device.
2. Description of Related Art
A projection device generates a light beam normally by at least one light emitting unit. The light beam is able to be modulated to be different light beams of image, which are then projected to a screen. Therefore, the light emitting unit is one of an essential element in the projection device. However, the light emitting unit as a heat source can generate huge amount of heat after running for a long time. If the heat fails to be dissipated in time external to the projection device, the temperature of the light emitting unit can be raised to a level capable of reducing the lifetime of the light emitting unit or simply damaging of the light emitting unit. Therefore, the projection device needs to include a heat dissipation device which is able to dissipate the heat efficiently.
A conventional dissipation device may include a fan for guiding cooling flow to the heat source of the light emitting unit so as to dissipate the heat and drop the temperature of the light emitting unit. However, the relative positions of the fan and a hot spot with the highest temperature of the heat source can be different when the projection device is operated at different projection directions. In other words, when the projection device is at certain projection directions, the fan cannot efficiently guide the cooling flow to the hot spot with the highest temperature of the heat source, such that the temperature of the entire heat source of the light emitting unit, or the temperature difference between the highest temperature and the lowest temperature of the heat source, can be overly high to damage the light emitting unit.